6,041 research outputs found
Monitoring Mosquito Larvae Population Density in the Ballona Wetlands Freshwater Marsh
Mosquitoes play an important role in wetland ecosystems. Their larvae feed on algae and plankton, and also provide a valuable food source for migrating bird species. However, adult mosquitoes can be a public health concern due to their possible transmittance of vector-borne diseases. The importance of protecting both the ecosystems used by mosquitoes and public health has prompted the monitoring of mosquito populations in the BallonaWetlands. This research aims to investigate and understand how the freshwater marsh supports the early life history stages of mosquitoes, and what role the BallonaWetlands play in mosquito population dynamics in west Los Angeles. The work presented here is the first phase: a pilot study that tests the utility of field-based surface water sampling methods to quantify the abundance and diversity of mosquito larvae in the freshwater marsh. This experimental study will provide temporal data of the appearance of mosquitoes in the wetlands, report population abundances of mosquito larvae, pupae and eggs, and discern the specific locations that contain the highest densities of mosquitoes.https://digitalcommons.lmu.edu/cures_posters/1024/thumbnail.jp
Rethinking Animal Agriculture: A Principlist Approach
Engrained in the mindless routines of our daily lives, we believe our consumer choices do not matter. But participating in the animal industrial complex through the purchase and consumption of meat, dairy and eggs generates significant bioethical issues that warrant exploration and discussion. This paper examines the moral rights of animals, poor ethical justification of animal consumption, and extreme ramifications of the animal agricultural system within the framework of principlism. By analyzing the moral position of animal consumption in the bioethical context of utility, autonomy, nonmaleficence, beneficence and justice, the corrupt nature of animal agribusiness is revealed and plant-based living encouraged as a strategy for moving forward
The Met receptor tyrosine kinase prevents zebrafish primary motoneurons from expressing an incorrect neurotransmitter
Information based clustering
In an age of increasingly large data sets, investigators in many different
disciplines have turned to clustering as a tool for data analysis and
exploration. Existing clustering methods, however, typically depend on several
nontrivial assumptions about the structure of data. Here we reformulate the
clustering problem from an information theoretic perspective which avoids many
of these assumptions. In particular, our formulation obviates the need for
defining a cluster "prototype", does not require an a priori similarity metric,
is invariant to changes in the representation of the data, and naturally
captures non-linear relations. We apply this approach to different domains and
find that it consistently produces clusters that are more coherent than those
extracted by existing algorithms. Finally, our approach provides a way of
clustering based on collective notions of similarity rather than the
traditional pairwise measures.Comment: To appear in Proceedings of the National Academy of Sciences USA, 11
pages, 9 figure
Mechanisms of growth cone repulsion
Research conducted in the last century suggested that chemoattractants guide cells or their processes to appropriate locations during development. Today, we know that many of the molecules involved in cellular guidance can act as chemorepellents that prevent migration into inappropriate territories. Here, we review some of the early seminal experiments and our current understanding of the underlying molecular mechanisms
Particle Size Distribution in Aluminum Manufacturing Facilities.
As part of exposure assessment for an ongoing epidemiologic study of heart disease and fine particle exposures in aluminum industry, area particle samples were collected in production facilities to assess instrument reliability and particle size distribution at different process areas. Personal modular impactors (PMI) and Minimicro-orifice uniform deposition impactors (MiniMOUDI) were used. The coefficient of variation (CV) of co-located samples was used to evaluate the reproducibility of the samplers. PM2.5 measured by PMI was compared to PM2.5 calculated from MiniMOUDI data. Mass median aerodynamic diameter (MMAD) and concentrations of sub-micrometer (PM1.0) and quasi-ultrafine (PM0.56) particles were evaluated to characterize particle size distribution. Most of CVs were less than 30%. The slope of the linear regression of PMI_PM2.5 versus MiniMOUDI_PM2.5 was 1.03 mg/m3 per mg/m3 (± 0.05), with correlation coefficient of 0.97 (± 0.01). Particle size distribution varied substantively in smelters, whereas it was less variable in fabrication units with significantly smaller MMADs (arithmetic mean of MMADs: 2.59 μm in smelters vs. 1.31 μm in fabrication units, p = 0.001). Although the total particle concentration was more than two times higher in the smelters than in the fabrication units, the fraction of PM10 which was PM1.0 or PM0.56 was significantly lower in the smelters than in the fabrication units (p < 0.001). Consequently, the concentrations of sub-micrometer and quasi-ultrafine particles were similar in these two types of facilities. It would appear, studies evaluating ultrafine particle exposure in aluminum industry should focus on not only the smelters, but also the fabrication facilities
Ischemic Heart Disease Incidence in Relation to Fine versus Total Particulate Matter Exposure in a U.S. Aluminum Industry Cohort.
Ischemic heart disease (IHD) has been linked to exposures to airborne particles with an aerodynamic diameter <2.5 μm (PM2.5) in the ambient environment and in occupational settings. Routine industrial exposure monitoring, however, has traditionally focused on total particulate matter (TPM). To assess potential benefits of PM2.5 monitoring, we compared the exposure-response relationships between both PM2.5 and TPM and incidence of IHD in a cohort of active aluminum industry workers. To account for the presence of time varying confounding by health status we applied marginal structural Cox models in a cohort followed with medical claims data for IHD incidence from 1998 to 2012. Analyses were stratified by work process into smelters (n = 6,579) and fabrication (n = 7,432). Binary exposure was defined by the 10th-percentile cut-off from the respective TPM and PM2.5 exposure distributions for each work process. Hazard Ratios (HR) comparing always exposed above the exposure cut-off to always exposed below the cut-off were higher for PM2.5, with HRs of 1.70 (95% confidence interval (CI): 1.11-2.60) and 1.48 (95% CI: 1.02-2.13) in smelters and fabrication, respectively. For TPM, the HRs were 1.25 (95% CI: 0.89-1.77) and 1.25 (95% CI: 0.88-1.77) for smelters and fabrication respectively. Although TPM and PM2.5 were highly correlated in this work environment, results indicate that, consistent with biologic plausibility, PM2.5 is a stronger predictor of IHD risk than TPM. Cardiovascular risk management in the aluminum industry, and other similar work environments, could be better guided by exposure surveillance programs monitoring PM2.5
Cash Transfers and Temptation Goods: An Analysis on the Impact of Cash Transfers on Poor Households’ Consumption of Sugar-sweetened Beverages in the Philippines
Sugar intake has been increasing globally and locally for individuals. Meanwhile, Philippine institutions continue to provide cash transfers (CTs) to poor households. Past literature found varying results of the impact of transfers on expenditure, consumption, and temptation goods. Most studies focused on alcohol and tobacco consumption and neglected the impact of cash transfers on the consumption of sugar-sweetened beverages (SSBs). Thus, this paper used propensity score matching and average treatment effects on the treated (ATET) evaluation method to compare the consumption of poor households with transfers to their consumption if they had not received cash transfers and determine the characteristics of households who were likely to receive transfers. The likelihood of poor households receiving CTs was significantly affected by some of the household head’s characteristics (age, educational attainment, and class of worker), household characteristics (household type, number of children below 18 years old, salaries and wages, and region of residence), and household facilities (water source, type of toilet facility, and type of roof). CTs were found to significantly decrease soft drinks consumption but did not significantly affect consumption of other SSBs. Policy responses related to increasing awareness of the health effects of these drinks like requiring warning labels, monitoring advertisements, and imposing restrictions on the amount of sugar added are highly recommended to decrease consumption of the said beverages
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